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/** @file
* High memory node enumeration DXE driver for ARM Virtual Machines
*
* Copyright (c) 2015-2016, Linaro Ltd. All rights reserved.
*
* SPDX-License-Identifier: BSD-2-Clause-Patent
*
**/
#include <Library/BaseLib.h>
#include <Library/DebugLib.h>
#include <Library/DxeServicesTableLib.h>
#include <Library/PcdLib.h>
#include <Library/UefiBootServicesTableLib.h>
#include <Protocol/Cpu.h>
#include <Protocol/FdtClient.h>
EFI_STATUS
EFIAPI
InitializeHighMemDxe (
IN EFI_HANDLE ImageHandle,
IN EFI_SYSTEM_TABLE *SystemTable
)
{
FDT_CLIENT_PROTOCOL *FdtClient;
EFI_CPU_ARCH_PROTOCOL *Cpu;
EFI_STATUS Status, FindNodeStatus;
INT32 Node;
CONST UINT32 *Reg;
UINT32 RegSize;
UINTN AddressCells, SizeCells;
UINT64 CurBase;
UINT64 CurSize;
UINT64 Attributes;
EFI_GCD_MEMORY_SPACE_DESCRIPTOR GcdDescriptor;
Status = gBS->LocateProtocol (&gFdtClientProtocolGuid, NULL,
(VOID **)&FdtClient);
ASSERT_EFI_ERROR (Status);
Status = gBS->LocateProtocol (&gEfiCpuArchProtocolGuid, NULL,
(VOID **)&Cpu);
ASSERT_EFI_ERROR (Status);
//
// Check for memory node and add the memory spaces except the lowest one
//
for (FindNodeStatus = FdtClient->FindMemoryNodeReg (FdtClient, &Node,
(CONST VOID **) &Reg, &AddressCells,
&SizeCells, &RegSize);
!EFI_ERROR (FindNodeStatus);
FindNodeStatus = FdtClient->FindNextMemoryNodeReg (FdtClient, Node,
&Node, (CONST VOID **) &Reg, &AddressCells,
&SizeCells, &RegSize)) {
ASSERT (AddressCells <= 2);
ASSERT (SizeCells <= 2);
while (RegSize > 0) {
CurBase = SwapBytes32 (*Reg++);
if (AddressCells > 1) {
CurBase = (CurBase << 32) | SwapBytes32 (*Reg++);
}
CurSize = SwapBytes32 (*Reg++);
if (SizeCells > 1) {
CurSize = (CurSize << 32) | SwapBytes32 (*Reg++);
}
RegSize -= (AddressCells + SizeCells) * sizeof (UINT32);
Status = gDS->GetMemorySpaceDescriptor (CurBase, &GcdDescriptor);
if (EFI_ERROR (Status)) {
DEBUG ((DEBUG_WARN,
"%a: Region 0x%lx - 0x%lx not found in the GCD memory space map\n",
__FUNCTION__, CurBase, CurBase + CurSize - 1));
continue;
}
if (GcdDescriptor.GcdMemoryType == EfiGcdMemoryTypeNonExistent) {
Status = gDS->AddMemorySpace (EfiGcdMemoryTypeSystemMemory, CurBase,
CurSize, EFI_MEMORY_WB);
if (EFI_ERROR (Status)) {
DEBUG ((EFI_D_ERROR,
"%a: Failed to add System RAM @ 0x%lx - 0x%lx (%r)\n",
__FUNCTION__, CurBase, CurBase + CurSize - 1, Status));
continue;
}
Status = gDS->SetMemorySpaceAttributes (CurBase, CurSize,
EFI_MEMORY_WB);
if (EFI_ERROR (Status)) {
DEBUG ((DEBUG_WARN,
"%a: gDS->SetMemorySpaceAttributes() failed on region 0x%lx - 0x%lx (%r)\n",
__FUNCTION__, CurBase, CurBase + CurSize - 1, Status));
}
//
// Due to the ambiguous nature of the RO/XP GCD memory space attributes,
// it is impossible to add a memory space with the XP attribute in a way
// that does not result in the XP attribute being set on *all* UEFI
// memory map entries that are carved from it, including code regions
// that require executable permissions.
//
// So instead, we never set the RO/XP attributes in the GCD memory space
// capabilities or attribute fields, and apply any protections directly
// on the page table mappings by going through the cpu arch protocol.
//
Attributes = EFI_MEMORY_WB;
if ((PcdGet64 (PcdDxeNxMemoryProtectionPolicy) &
(1U << (UINT32)EfiConventionalMemory)) != 0) {
Attributes |= EFI_MEMORY_XP;
}
Status = Cpu->SetMemoryAttributes (Cpu, CurBase, CurSize, Attributes);
if (EFI_ERROR (Status)) {
DEBUG ((EFI_D_ERROR,
"%a: Failed to set System RAM @ 0x%lx - 0x%lx attribute (%r)\n",
__FUNCTION__, CurBase, CurBase + CurSize - 1, Status));
} else {
DEBUG ((EFI_D_INFO, "%a: Add System RAM @ 0x%lx - 0x%lx\n",
__FUNCTION__, CurBase, CurBase + CurSize - 1));
}
}
}
}
return EFI_SUCCESS;
}
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